SETI is the Search for Extraterrestrial Intelligence.
SETI uses radiotelescopes worldwide to search for, well,
extraterrestrial intelligence, I guess. Anyway, several
years ago the SETI people realized that, although they
were gathering massive amounts of data, they would never
have the computer time to analyze it all. So they dreamed
up SETI-at-Home. Participants, like me and about 3
million others, load an analysis program onto their home
computers that analyzes SETI data when they are not using
their computer. SETI-at-Home runs like a screensaver,
activating when your normal screensaver would activate.
The program contacts the internet to receive data and to
send results of its analysis. If you'd like to
participate or just find out more about SETI-at-Home go to their homepage.